Rolling mill for pierced or solid metal blanks



June 1 1926.

v J. GASSEN ROLLING PKILL FOR PIERCE!) 03 SOLID METAL BLANKS Original il F 13. 1922 o t n fm f a M 1 f. v

Patented June 1, 1926.-

UNITED STATES JOSE]? GASSEN, F DUSSELDORF-RATH, GERMANY.

ROLLING MILL FOB PIERCED OR SOLID METAL BLANKS.

Original application filed February 13, 1822, Serial No. 535,998, and in Sweden, September 7, 1921. Divided and,this application filed February 6, 1925. swarm. 7,259.

This invention relates to an improvedrolling mill for pierced or solid metal blanks and constitutes a division of the subjcct matter of my pending application for 5 patent. Serial No. 535,998, filed; February The rolling of metal stock by means of one or more pairs of rolls and the use of said rolls of conical form in connection with a conical mandrel to produce seamless metal tubes, is now well known in the art.

My present improvements are primarily characterized by the fact that one pair of rolls is of conical form, while the other pair 1 of rolls is of disc or wheel shaped form, said rolls being so arranged relative to each other as to form a continuous pass for the stock. In a mill of this kind the finishing operation follows closely upon the preparation of the stock in the formation of the bore or cavity, but is effected by a different set of rolls. These rolls may vary in their arrangement as well as in their peripheral speed, so that the possible tearing or disintegration of the metal blank at any point of contact of the rolls therewith may be entirely prevented.

Preferably the disc rolls are rotated in relatively opposite directions and the axes of these disc rolls are located in diflerent horizontal planes respectively above and below a horizontal plane intersecting the axis of the metal blank. The disc rolls are arranged to provide convergently related working faces forming a narrowing pass for the metal blank, and the conical finishing rolls are arranged with respect to said disc,

rolls to provide a widening pass for the metal blank as it moves over the bore forming mandrel, said conical rolls being rotated in the same direction. Owing to the fact that the finishing of thebore or cavity takes place immediately after the preparatory operation of the disc rolls, access of oxygen to the cavity is precluded, both pairs of rolls operating simultaneously upon the material in connection with the mandrel and insuring the steady advance of the material through the pass formed by said rolls and over the mandrel.

"With the above and-other objects in View, in the accompanying drawing I have illustrated several practical forms of the invention which, in its preferred embodiment,

consists of a certain relative arrangement of the several cooperating elements, as will be hereinafter more particularly described, illustrated in the accompanying drawing and subsequently incorporated in the subjoined claims.

In the drawing, wherein similar reference characters designate corresponding parts throughout the'severalviews,

Figure 1 is a side elevation of one practical form of my improved rolling mill.

Figure 2 is a plan view thereof.

Figure 3 is a view similar to Figure'l,

illustrating a slightly modified formof the p I invention; and Figure 4 1s a plan viewof the construction shown 1n Figure 3.

Referring first more particularly to Fig- I ures 1 and 2 of the drawings, the two disc rolls Band 6 are arranged in spaced relation to each other and have their axes of rotation located out of or in spaced relation to a horizontal plane intersecting the major axial line of the metal blank 7 to be rolled or operated upon. Vertical planes passing through the axes of the rolls 5 and 6 intersect each other on the axial line of the blank 7, said spaced disc rolls having their axes angularly disposed relative to each other and arranged with relation to the axial line of the blank 7 so as to form an angle of more than 90 degrees as indicated at 8. This arrangement of the disc rolls is clearly illustrated in Figure 2 of the drawings, and it will be noted that in such arrangement the axes of said rolls are respectively equidistant-1y spaced above and below the horizontal plane which intersects the axis of the blank 7 (see Figure 1).

From the above it will be observed that,

the inner opposed working faces 9 of the disc rolls 5 and 6 are convergently related to each other in the direction of movement of the metal blank. There is thus formed a narrowingpass for the blank, the working faces of said rolls exerting'a gradually increasing compressing action upon the metal blank, so that its originally circular cross sectional shape or form is altered into a somewhat elliptical cross sectional shape. lin the arrangement described the rolls 5- and 6 are rotated in. relatively opposite directions, as indicated by the arrows in Figure 2 of the drawing, so that the working faces of said rolls forming the narrowing pass for the stock move in relatively opposite directions in contact with the opposite sides of the stock and impart a continuous rotation thereto while exerting a transverse compressing pressure on the metal blank.

At the egress side of the narrowing pass formed by the disc rolls 5 and 6 the stationary bore forming-mandrel 10 is arranged. The conical rolls 11 and 12 associated with the disc rolls 5 and 6 respectively are positioned in opposite sides of the mandrel 10 so that the line of contact of the peripheral surface of these rolls on the metal blank is substantially a continuation of the working faces of the disc rolls 5 and 6. The conical rolls are arranged with their axes obliquely disposed in relatively opposite directions, extending above and below a horizontal plane, passing through the axial center line of the mandrel 10 and of the metal blank. As seen in Figure 2, the axes of these conical rolls also diverge, so that together they form a gradually widening pass for the'blank as it moves over the surface of the mandrel 10. In the movement of the blank through the widening section of the pass the material undergoes a further change and is restored to its substantially original circular cross sectional form. The formation of the bore orcavity is simultaneously completed by the fixed mandrel 10, so that the finishing operation whereby the seamless metal tube is produced follows immediately after the preparatory action of the disc rolls 5 and 6 upon the metal blank.

In Figures 3 and 4 of the drawings I have illustrated a slightly modified form of the invention, in which instead of arranging the disc rolls with their axes intersecting each other and disposed in horizontal planes above and below the axis of the blank, I arrange these rolls 5 and 6 respectively with their axes disposed in parallel relation to each other, said rolls having the beveled working faces 5 and 6 forming the narrowing pass for, the metal blank. In this case the axes of rotation of the'two disc rolls are arranged in the same horizontal plane and either above or below the axial center line of the metal blank, as may be preferred. In conjunction with these disc rolls which are rotated in'the same direction, the conical rolls 11 and 12 are associated and arranged with respect to the fixed bore forming mandrel substantially in the same manner as above described. However, it will be noted that one side of the disc roll 6' is provided with a recess or chamber 6 which receives the conical roll 12 so that said roll may be arranged where- .by its peripheral. surface in effect constiemplified in other alternative constructions.

Accordingly I reserve the privilege of resorting to all such legitimate changes in the form, construction and relative arrangement of the several parts, as may be fairly embodied within the spirit and scope of the invention as claimed.

What I claim is:

1. In a rolling mill for producing seamloss hollow bodies from pierced or solid metal blanks, a bore forming mandrel. a pair of disc rolls arranged in spaced relation to each other and having their axes of rotation disposed in spaced relation to a horizontal plane passing through the major axial line of a blank moving between said disc rolls, said rolls having opposed converging working faces forming a narrowing pass for the blank, and a pair of conical rolls arranged respectively on opposite sides of said mandrel and associated with the re-- speotive disc rolls to form a widening pass for the metal blank.

:2. In a rolling mill for the production of seamless hollow bodies from pierced or solid metal blanks, a bore forming mandrel, a

pair ofdisc rolls arranged in spaced relation to each other and adapted to be rotated in relatively the same direction, said rolls having their axes of rotation disposed in the same horizontal plane, respectively distanced from a horizontal plane passing through thecentral axial line of the metal blank. said rolls having convergently related working faces forming a narrowing pass for the blank, a bore forming mandrel at the egress side of said pass, and conical .rolls adapted to be rotatedin the same direction and arranged uponopposite sides of said mandrel, said rolls associated respectively with said disc rolls and having their peripheral faces positioned with relation to the working faces of such disc rolls to produce in conjunction therewith a continuation of the pass gradually increasing in area.

In testimony that Iclaim the foregoing as my invention, I have signed my name hereto.

J OSEF GASSEN. 

